"The Dark Web" is a fancy way to describe websites that are only accessible through the Tor Network or I2P. The easiest way to access Tor is through the
Tor browser.
Once you can access Tor, use a
Hidden Wiki (a directory of interesting links).
Beware, there's lots of nasty things on there, so if you're sensitive to a few things think twice before clicking through links (it will not jump at you from nowhere though).